The present invention relates to a polymer containing, as a monomer unit, acrylic acid, acrylic acid ester, acrylamide, acrylonitrile and the like to whose carbon atom at .alpha.-position is introduced a hydrophilic radical. Particularly, the present invention relates to a functional polymer containing, as a monomer unit, 2-hydroxy acrylic acid, 2-hydroxy acrylic acid ester, 2-hydroxy acrylonitrile, and the like which are useful as functional polymers in medical, cosmetic and electronic industrial chemical fields.
Polymers comprising acrylic acid, methacrylic acid or their esters as a monomer unit have been well known and many of those polymers have been practically utilized as water-absorbing polymers, polymers for chemical fibers, polymers for electron beams type resists, etc. Further, polymers having .alpha.-acyloxy acrylic acid ester as a monomer unit has been reported (for instance, U.S. Pat. No. 2,559,635). Still further, polymers containing, acrylic acid ester as a monomer unit, to whose carbon atom at .alpha.-position is bound an acyl group, an alkoxy group, an alkylthio group, etc. have been reported (for instance, Japanese Patent Publication- Kokai-Nos.324201/1994, 294980/1994, etc.). However, those polymers do not satisfy such requirements on functions as water-holding ability, water-absorbing ability, adhesive force to semi-conductor substrate, heat resistance, etc.
Polymers comprising acrylic acid, methacrylic acid or their esters as a monomer unit have been practically utilized in many fields of technologies. In those polymers, carboxyl groups or esterified carboxy groups pending on the main chain show the functionality. However, recently, it has strongly been desired in medical, cosmetic and electronic industrial chemical fields that highly functional polymers having improved water-holding ability, water-absorbing ability, adhesive force to semi-conductor substrate and heat resistance are to be developed.